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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
501

Carcajou (Gulo gulo), sociétés et conservation dans le Nord canadien

Bonamy, Morgane 09 1900 (has links)
Cette recherche propose comme objectif d’étudier les relations entre le carcajou et les populations locales et autochtones du Canada, dans différentes régions d’études et dans un site de conservation ex-situ. Ceci afin de mieux comprendre leurs rapports et interactions avec cet animal et de pouvoir adapter les modes de gestion de l’espèce aux besoins des sociétés mais aussi en fonction du contexte socio-culturel local. Plus particulièrement, cette étude explore d’une part les relations entre Premières Nations et le carcajou, ainsi que les perceptions et les représentations sociales que différents groupes de la société (Ainés, chasseur, trappeurs, enfants autochtones/non-autochtones) ont de cet animal, et d’autre part le rôle que joue cette espèce, en contexte de conservation ex-situ : à savoir dans un jardin zoologique, sur les connaissances et la motivation du public envers la protection du carcajou. Pour ce faire, nous avons utilisées différentes méthodes (entrevues semi-dirigées, questionnaires, dessins, observation participante) sur trois sites d’études en fonction de l’absence/présence du carcajou. Ainsi, nous avons étudié les interactions humains-carcajous dans la région North Slave dans les Territoires du Nord-Ouest auprès des populations non autochtones et autochtones (les Premières Nations Dénée et Métis), où le carcajou cohabite avec les sociétés. Nous nous sommes également intéressés à la représentation du carcajou par les membres de la Nation Naskapie au Nord du Québec et de la Nation Dénée dans les Territoires du Nord-Ouest, où le carcajou n’est plus présent depuis 40 ans. Enfin, un dernier terrain au Zoo de St Félicien au Québec nous a permis d’analyser la place de ce carnivore dans la conservation ex-situ pour le public québécois. Les résultats ont mis en évidence, que les Premières Nations Dénées et Métis possèdent des connaissances très approfondies sur cet animal, qu’elles admirent et respectent, et ont souligné l’importance de la participation des populations et des savoirs traditionnels dans les projets de protection et conservation de cette espèce. L’analyse des connaissances et perceptions des enfants a montré que même si le carcajou ne leur est pas inconnu, de nombreuses lacunes sur l’espèce sont présentes reflétant un manque de connaissance général sur cet animal. Cependant, le carcajou reste un animal relativement bien représenté en dessin par les enfants, même si peu d’enfants connaissent son rôle écologique. Il existe quelques différences dans la représentation de l’animal selon le territoire/province dans lequel les enfants habitent. Les données collectées au sein du zoo ont indiqué que le public, d’une région où le carcajou a disparu, ne connait pas bien le carcajou, bien qu’il évalue positivement l’intérêt de cette espèce au sein du zoo. De manière prometteuse, exposer le grand public à cette espèce dans les zoos ou dans des camps d’été pour enfants semble être un moyen efficace pour promouvoir des attitudes positives à l’égard de cette espèce et encourager le soutien des populations envers sa conservation. Ces résultats montrent qu'il est nécessaire de mener des programmes alternatifs de sensibilisation et d'information du public au vu de la conservation et de la gestion du carcajou, en particulier dans les zones où de nouveaux programmes de gestion peuvent être mis en œuvre, afin d'accroître l'acceptation de cette espèce par la société et de sensibiliser le public à ce carnivore incompris. Cette étude souligne aussi l’importance de la participation des populations locales, adultes et enfants dans les programmes de conservation et gestion des espèces afin de garantir leur succès. De plus, les savoirs traditionnels et leur intégration dans la recherche scientifique devraient bénéficier d'une plus grande valeur. Enfin, les programmes de conservation doivent prendre en compte les souhaits des populations locales et collaborer avec elles, afin d’obtenir un plus grand succès. / The objective of this research is to investigate the relationships between local or First Nation people in Canada and wolverines, in different study areas and an ex-situ conservation site. In doing so, we hope to improve our understanding of these relationships and interactions with this species in order to adapt management policies and improve their fit with society’s needs and the local socio-cultural context. On the one hand, this study explores relations between First Nation peoples and the wolverine as well as the perceptions and social representations of this species by different societal groups (Elders, hunters, trappers, Indigenous/non-Indigenous children). On the other hand, it tries to understand the role played by wolverines in the context of ex-situ conservation (i.e. in a zoo) and knowledge and motivation by the public towards the protection of this species. We addressed these goals through the use of multiple different methods: semi-directed interviews, questionnaires, drawings, and participant observation, and applied these techniques in three separate study sites, both with and without wolverines. For example, we studied human-wolverine interactions in the North Slave region of the Northwest Territories with Indigenous populations (Dene and Métis First Nations), where people share the land with wolverines, gathering information from both adults and children alike. We then contrasted the knowledge and perceptions of these children with those of a second group that no longer have regular contact with this species, the Naskapi Nation in northern Quebec. Finally, at the St Félicien Zoo in Quebec, we qualitatively assessed the willingness of the general public to support conservation measures for this carnivorous species. Results indicated that Dene and Métis First Nations have a very deep knowledge of this species, which they admire and respect, which emphasized the importance of participation by First Nation peoples in the implementation of conservation programs for this species. In analyzing children's knowledge and perceptions, we found that while many children possess a basic knowledge about wolverines, there are numerous gaps in that knowledge which, if filled, may benefit future conservation efforts. Despite these gaps, the wolverine was relatively well represented in drawings by children, though their ecological role may remain be cloudy to some, and differences in their portrayal were apparent among territories/provinces in which children live. Data collected in the zoo indicate that the general public, in a region where wolverines have become extirpated, lack some general knowledge about this species and that the level of knowledge is not equal across the greater public. Promisingly, exposure to wolverines at the zoo or through children's camps does seem to promote positive attitudes towards this species and foster support for their conservation. These results shows that there is a need for increased awareness and public information programs for wolverine conservation, particularly in areas where new management programs may be implemented, to increase social acceptance of this species and raise public knowledge about this misunderstood carnivore. An integration of local populations, both children and adults, is necessary for a better legibility of management of the animal; as well as the valorization of traditional knowledge and its integration in scientific research. For the success of a species management program, it is inevitable to ask the people what they want and support the project. This study emphasizes the importance of participation by local populations, both adults and children, in conservation management plans for their success. Additionally, greater value should be assigned to traditional knowledge and its integration into scientific research. Finally, conservation programs must acknowledge the desires of the local populations and work together with local stakeholders if they wish to succeed.
502

Estandarización de las etapas de creación del modelo de pre-mezcla, mina El Teniente

Soto Ugarte, Claudio Ignacio January 2017 (has links)
Ingeniero Civil de Minas / Alrededor de los últimos 100 años, la minería por medio de Caving ha sido aplicada provechosa y convenientemente en la extracción de los cuerpos mineralizados. Sin embargo, cuando estos métodos son aplicados, parte del recurso mineral no es incorporado en los planes de extracción, ya sea por encontrarse fuera de la envolvente económica en altura, desviaciones en la operación o al cierre anticipado por ingreso de dilución y/o agua barro. Este material remanente es denominado como recursos quebrados, de los cuales aproximadamente, el 10% de éstos se incorporará a los planes como reservas mineras solo por el efecto de la dilución con el mineral In Situ. Dadas las nuevas condiciones de mercado y la longevidad de los yacimientos, los recursos quebrados se muestran atractivos en cuanto a su ley. Es por esto que se han desarrollado algunos modelos con el objetivo de describir este tipo de material en términos de tonelaje y ley. Sin embargo, esto es un problema complejo, debido a que no se puede aplicar geoestadística a este tipo de material, ya que a lo largo del tiempo el mineral ha sido desplazado, mezclado y degradado en términos metalúrgicos, por lo que existe una alta variabilidad en las estimaciones realizadas. Pese a lo anterior, se vuelve aceptable un mayor rango de error en la estimación del quebrado, ya que, al ser un mineral remanente, este presenta un costo marginal en su extracción. Una vez creado el modelo de bloques de material quebrado se superpone en el modelo de bloques In Situ, generando así el modelo pre-mezcla. En este contexto, este trabajo busca estandarizar el proceso de creación del modelo pre-mezcla, en base a la metodología que usa actualmente la mina El Teniente. Los principales resultados obtenidos al estandarizar el proceso, son la posibilidad de identificar los indicadores claves del proceso (KPI) y las etapas críticas en la creación del modelo pre-mezcla. Así es como se reconocen tres puntos de control dentro del proceso. El primero, es verificar por medio de un análisis estadístico que el modelo In Situ es el adecuado y no contiene errores. Luego, mediante el uso del software Matlab, identificar qué sectores participan en la creación del modelo quebrado y finalmente, realizar un chequeo a través de los programas Access y Vulcan, que garantice que el modelo pre-mezcla es el apropiado para generar el modelo de bloques diluido. Lo anterior, permite gestionar las desviaciones de manera temprana, disminuyendo así los reprocesos. Además, se establece una automatización a una parte del proceso, lo que minimiza la probabilidad de incurrir en errores asociados a la manipulación de datos.
503

Development of a Multi-Body Autonomous Inspection Robot for Small Diameter Pipes

Garcia Almanza, Cuautli Ignacio 10 September 2020 (has links)
The most common way to transport oil and natural gas in Canada is by using pipes. In the last years, population growth has led to an increase in the pipeline network. This increase will generate new areas of research such as the detection of leakages or cracks and the maintenance of the pipeline system as a whole. In this thesis, a novel hypermobile robot, capable of moving along pipes of different diameters, is proposed and developed. The robot is composed of three modules, two propulsive modules and one control module linked by passive joints. The propulsive module has eight actuators: four gearmotors to propel the robot along the pipe, and four servomotors to control the radial position of the robot in the pipe and to maintain the robot's balance. A Raspberry Pi is used to control the actuators, acquire sensor feedback, and receive commands from a remote wireless user-controlled GUI. An existing dynamic controller is adapted to the robot's architecture. Simulations and experimental tests in open-loop and closed-loop modes are performed to evaluate the effectiveness of the robot's design and controller. The results show the efficiency of the mechanical and electronic components of the robot since it is capable of following the generated paths. The outcome of this thesis can be used in trajectory tracking controllers and for in-pipe robot design.
504

Spectro-Electrochemical Study of Staging in Graphitic Electrodes for Aluminum Batteries

Wee, Shianlin 14 November 2019 (has links)
After three decades of commercialization, graphite remains the preferred active material for intercalation-type Li-ion battery anodes. Still, the characterization of staging continues to be elusive at the sub-micro- and nano-scales, the typical dimensions of graphite crystallites. Here, the intercalation of Al-based anions in graphitic materials was studied using X-ray powder diffraction (XRD) and Raman spectroscopy. While, in the first case, the analysis was done ex-situ and in mm3-samples, a more localized view was provided by the laser probe which could, furthermore, interrogate the electrochemical process in real-time (in-situ). To do this, an electrochemical cell for Raman studies was custom-made for Al batteries working with non-aqueous electrolytes. Two C materials were used: natural graphite (NG) and processed expandable graphite (EG). Owing to the smaller flake size, higher graphitization degree and larger crystallites of the NG, the Al/NG cells exhibited better performance than the Al/EG ones. Interestingly, discrepancies were observed in the stage numbers estimated from XRD and Raman. These were thought to arise from the, respectively, long- and short-range atomic order scales that are analyzed by those two techniques. To confirm this, in-situ Raman multi-point studies were performed. The results show the presence of domains with mixed stage graphite intercalation when the cells were fully charged, explaining the staging discrepancies.
505

Regeneration of gingival tissue using in situ tissue engineering with collagen scaffold / 生体内再生の手法によるコラーゲン足場を用いた歯肉組織の再生

Hatayama, Takahide 23 July 2019 (has links)
京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第13265号 / 論医博第2179号 / 新制||医||1038(附属図書館) / (主査)教授 別所 和久, 教授 安達 泰治, 教授 戸口田 淳也 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM
506

Study on thin film fabrication process and electrode reaction analysis for high efficiency solid oxide fuel cell / 固体酸化物形燃料電池の高効率化に向けた薄膜作製プロセスおよび電極反応解析に関する研究

Tsuji, Yoichiro 24 November 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(人間・環境学) / 甲第22859号 / 人博第967号 / 新制||人||229(附属図書館) / 2020||人博||967(吉田南総合図書館) / 京都大学大学院人間・環境学研究科相関環境学専攻 / (主査)教授 内本 喜晴, 教授 吉田 寿雄, 准教授 戸﨑 充男 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DFAM
507

In-situ Non-destructive Studies on Biofouling Processes in Reverse Osmosis Membrane Systems

Farhat, Nadia 12 1900 (has links)
Reverse osmosis (RO) and nanofiltration (NF) membrane systems are high-pressure membrane filtration processes that can produce high quality drinking water. Biofouling, biofilm formation that exceeds a certain threshold, is a major problem in spiral wound RO and NF membrane systems resulting in a decline in membrane performance, produced water quality, and quantity. In practice, detection of biofouling is typically done indirectly through measurements of performance decline. Existing direct biofouling detection methods are mainly destructive, such as membrane autopsies, where biofilm samples can be contaminated, damaged and resulting in biofilm structural changes. The objective of this study was to test whether transparent luminescent planar oxygen sensing optodes, in combination with a simple imaging system, can be used for in-situ, non-destructive biofouling characterization. Aspects of the study were early detection of biofouling, biofilm spatial patterning in spacer filled channels, and the effect of feed cross-flow velocity, and feed flow temperature. Oxygen sensing optode imaging was found suitable for studying biofilm processes and gave detailed spatial and quantitative biofilm development information enabling better understanding of the biofouling development process. The outcome of this study attests the importance of in-situ, non-destructive imaging in acquiring detailed knowledge on biofilm development in membrane systems contributing to the development of effective biofouling control strategies.
508

Highly Multiplexed Single Cell In Situ Transcriptomic Analysis

January 2019 (has links)
abstract: Spatial resolved detection and quantification of ribonucleic acid (RNA) molecules in single cell is crucial for the understanding of inherent biological issues, like mechanism of gene regulation or the development and maintenance of cell fate. Conventional methods for single cell RNA profiling, like single-cell RNA sequencing (scRNA-seq) or single-molecule fluorescent in situ hybridization (smFISH), suffer either from the loss of spatial information or the low detection throughput. In order to advance single-cell analysis, new approaches need to be developed with the ability to perform high-throughput detection while preserving spatial information of the subcellular location of target RNA molecules. Novel approaches for highly multiplexed single cell in situ transcriptomic analysis were developed by our group to enable single-cell comprehensive RNA profiling in their native spatial contexts. Reiterative FISH was demonstrated to be able to detect >100 RNA species in single cell in situ, while more sophisticated approaches, consecutive FISH (C-FISH) and switchable fluorescent oligonucleotide based FISH (SFO-FISH), have the potential for whole transcriptome profiling at the single molecule sensitivity. The introduction of a cleavable fluorescent tyramide even enables sensitive RNA profiling in intact tissues with high throughput. These approaches will have wide applications in studies of systems biology, molecular diagnosis and targeted therapies. / Dissertation/Thesis / Doctoral Dissertation Chemistry 2019
509

Detecting patterns of upwelling variability in Eastern Boundary Upwelling Systems with special emphasis on the Benguela region

Abrahams, Amieroh January 2020 (has links)
Magister Scientiae (Biodiversity and Conservation Biology) / Coastal upwelling is one of the most important oceanographic processes relating to ecosystem function at local and global spatial scales. To better understand how changes in upwelling trends may occur in the face of ongoing anthropogenically induced climate change it is important to quantify historical trends in climatic factors responsible for enabling coastal upwelling. However, a paucity of conclusive knowledge relating to patterns concerning changes in upwelling across the world’s oceans over time makes such analyses difficult. In this study I aimed to quantify these patterns by first identifying when upwelling events occur using a novel method for predictingthe behaviours of coastal upwelling systems over time. By using remotely sensed SST data of differing resolutions as well as several wind variables I was able to identify and quantify upwelling signals at several distances away from the coastline of various upwelling systems. Using this novel method of determining upwelling, I then compared upwelling patterns within all Eastern Boundary Upwelling Systems (EBUS) over a period of 37 years, with the assumption that climate change was likely to have driven variable wind patterns leading to a more intense upwelling over time. Overall, upwelling patterns and wind variables did not intensify overtime. This method of identifying upwelling may allow for the development of predictive capabilities to investigate investigate investigate upwelling trends in the future.
510

In Situ RNA Quality Control : A spatial heat map of RNA integrity with single cell resolution

Carlberg, Konstantin January 2015 (has links)
The quality of RNA is of great importance in gene expression studies. It is mostly measured using the RNA integrity number (RIN). Lately it has been shown that samples with low RIN and different fragmentation patterns could affect quality of sequencing data. For such low RIN samples a new approach has been developed by Illumina called the DV200 metric, which is the percentage of fragments >200 nucleotides. For samples with low RIN, DV200 has proved to be a better method to predict if good quality data from RNA sequencing can be generated. However, neither RIN nor DV200 provide spatial infromation on the RNA integrity. Thus, tissues with areas of heterogeneous RNA integrity, where regions of good quality RNA sequencing data could be generated from are missed. We have designed a method to spatially evaluate the RNA integrity in tissue, which we named in situ RNA QC. The method uses three probes with three different fluorophores, each bound to three specific cDNA regions synthesized from the high abundant and well conserved 18S rRNA. With the help of in-house technology from the Spatial Transcriptomics (ST) group at SciLifeLab, we enable creation of heat maps over the RNA integrity to show spatial fragmentation patterns of RNA in tissue. This could reveal the regional quality of transcripts in situ, which is crucial knowledge when selecting samples for further RNA sequencing. The assay has been tried using different tissue fixation methods in order to show a proof of concept that formalin gives shorter cDNA fragments than acetone. The generated heat-map provides a visual overview of RNA integrity in situ; hence this method could be used to select samples for sequencing by evaluation the spatial quality of RNA. For instance from fresh frozen and formalin fixated paraffin embedded (FFPE) tissue (biobanks contain large number of longterm storage FFPE samples). With this assay we will be able to determine which samples are suitable for sequencing.

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